CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Total	First Banks, Inc. Stockholders’ Equity, Preferred Stock [Member]	First Banks, Inc. Stockholders’ Equity, Common Stock [Member]	First Banks, Inc. Stockholders’ Equity, Additional Paid-In Capital [Member]	First Banks, Inc. Stockholders’ Equity, Retained Earnings [Member]	First Banks, Inc. Stockholders’ Equity, Accumulated Other Comprehensive Income [Member]	Noncontrolling Interest [Member]
Balance, beginning of period at Dec. 31, 2013	$ 488,256	$ 13,373	$ 5,915	$ 324,913	$ 42,719	$ 7,502	$ 93,834
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,350				5,405		(55)
Other comprehensive income	3,700					3,700
Balance, end of period at Mar. 31, 2014	497,306	13,373	5,915	324,913	48,124	11,202	93,779
Balance, beginning of period at Dec. 31, 2014	512,444	13,373	5,915	324,913	64,374	10,111	93,758
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,683				2,674		9
Other comprehensive income	4,244					4,244
Balance, end of period at Mar. 31, 2015	$ 519,371	$ 13,373	$ 5,915	$ 324,913	$ 67,048	$ 14,355	$ 93,767